The Unfortunate Nurse:
A Case Study of Dengue Fever and Social Policy
by
Karen M. Aguirre, Biology Department, Coastal Carolina University, Conway, SC
BEFORE CLASS
Students should read the journal article, “Nosocomial Acquisition of Dengue,” by Dirk Wagner et al., Emerging
Infectious Diseases, vol. , no. , pp. –, October  (available online at
http://www.cdc.gov/ncidod/EID/volno/-.htm). This is the article that inspired
ed “The Case of the
glo economy air
Unfortunate Nurse.” The event described in the article occurred in Freiburg, Germany, but in a global
travel for business and recreation have shrunk our world to a “global village” where infection
on can sprea
spread rapidly.
Notice that the article appears in Emerging Infectious Diseases, a journal of the Centers for Disease Control (CDC). The
CDC is the agency of the United States government charged with monitoring
infections
itoring incidence and patterns of infe
in our country. The CDC is keenly aware of dengue infection. Endemic in Latin America and Puerto Rico as w
well as
other parts of the world, dengue infection could one day become more common
mmon in the continental U.S.
As you read the article, circle all of the terms that you do not understand.
d. You can find definitions for many of tthese
terms using the Medline Plus Medical Dictionary (http://www.nlm.nih.gov/medlineplus/mplusdictionary.html)
or
nih.gov/medlineplus/mplusdicti
the textbooks available on the PubMed Entrez Bookshelf (see Resources
with a few definitions, as
ources below). Be prepared
p
we will go over some of these new words next time class meets.. Also pay special attention
attentio to the information given in
the figure and the table in the article, but do not be concerned
understand. Do your
ned if there
ere is much that you do not u
best and we will demystify the rest together when we discuss
scuss the article
ticle in cla
class.
We also will generate a list of questions that require further research
accomplish the project outlines given
esearch if we are to acco
below:
• Approach a scientific paper without fear,
ar, identifying
ing and researching
researchin unknown
un
terminology.
• Become familiar with the idea of nosocomial
osocomial
al infection (note the title of the pre-class reading).
• Become familiar with the idea of emerging pathogens.
pathogens
ito vector/host
ost infection strategy
stra
• Explore the complex virus/mosquito
of dengue virus.
wing techniques:
ues: EIA (ELISA),
(ELISA
(E
• Become familiar with the following
differential cell counts, and RT-PCR (first
introduced in the pre-class reading).
ding).
• Explore the idea of “agenda”” in science and ethics
hi and
an politics in public policy-making.
• Learn to communicate information
nformation with special attention
a
to the intended outcome and the intended audience.
Resources
Note: Asterisked items  and
nd  are req
required reading for the case study. You may pick and choose from the rest of the list
as desired. Don’t be afraid
aid to look further than this list. All Internet addresses were active as of May , .
*. Wagner, D., de With,
Wi K., Huzly, D., Hufert, F., Weidmann, M., Breisinger, S., Eppinger, S., Kern, W.V.,
and Tilman,
an, M.
M.B. . Nosocomial acquisition of dengue. Emerging Infectious Diseases ():–
; see
ee http
http://www.cdc.gov/ncidod/EID/volno/-.htm.
ves-So
*. Neves-Souza,
P., Zeredo, E.L., Zagne, S., Valls-de-Souza, R., Reis, S., Cerqueira, D., Nogueira, R., and
Kubel C.F. . Inducible nitric oxide synthase (iNOS) expression in monocytes during acute dengue
Kubelka,
fe in patients and during in vitro infection. BMC Infectious Diseases :; see
fever
http://www.biomedcentral.com/-//.
“The Unfortunate Nurse” by Karen M. Aguirre
Page 
*. Dengue and Dengue Hemorrhagic Fever: Information for Health Care Practitioners,
http://www.cdc.gov/ncidod/dvbid/dengue/dengue-hcp.htm. Contains good diagrams/slides and other
information about the dengue virus, the mosquito vector, and the infectious strategy of the virus.
*. Better Environmental Management for Control of Dengue, World Health Initiative,
http://www.who.int/heli/risks/vectors/denguecontrol/en/index.html.
*. Blood Groups and Red Cell Antigens, NCBI,
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=rbcantigen.chapter.ch. Good textbook article on blood and
the cells it contains.
*. The White Blood Cell and Differential Count.
http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=cm.chapter. In: Clinical Methods, rd ed., H. Kenneth
Walker et al., Butterworths.
. Wikipedia has a good article on white blood cells with photographs that will help you see the
morphological differences that allow a trained microscopist to determine leukocyte number, lymphocyte
number, neutrophil number, etc.—i.e., to make a “differential count” of white blood cells. See:
http://en.wikipedia.org/wiki/White_blood_cell.
. EpiNotes Disease Prevention and Epidemiology Newsletter. South Carolina  List of Reportable
Conditions. http://www.scdhec.gov/health/disease/index.htm. Look at this to get an idea of what the
Reportable Disease forms look like, and where dengue sits on the list. Try to also find sites like this for
other southern and southwestern states, which have large Mexican immigrant populations, and Florida,
which has large populations of well-traveled retirees.
. Reiter, P., Lathrop, S., Bunning, M., Biggerstaff, B., Singer, D., Tiwari, T. et al. . Texas lifestyle limits
transmission of dengue virus. Emerging Infectious Diseases (): –. Available at
http://-www.cdc.gov.mill.sjlibrary.org/ncidod/eid/volno/-.htm.
. Medline Plus Medical Dictionary at http://www.nlm.nih.gov/medlineplus/mplusdictionary.html.
. PubMed’s Entrez BookShelf, at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Books, is a free,
searchable database of on-line college and medical life science textbooks. In the search box at the top of the
page, type in your search words (e.g., “ELISA”). Many of the books include downloadable figures, etc., that
you can use in your papers and presentations. Just be sure to cite your sources!
“The Unfortunate Nurse” by Karen M. Aguirre
Page 
Part I—The Unfortunate Nurse
As a class, we are going to act out the scenario below, with students taking the parts of the Narrator, Nancy, Dr. Ghee,
and Elaine (Dr. Ghee’s nurse).
Narrator:
It is July, and it’s sweltering in St. Louis, Missouri. A young woman named Nancy waits nervously in
the examining room of a local doctor. There’s air conditioning here, but the woman does not look very
comfortable. She sighs repeatedly and rubs her neck from time to time. After a brief wait, Elaine, the
nurse, enters and takes Nancy’s vital signs and updates her chart.
Elaine:
Well, your weight is down a few pounds from your last visit— pounds—and it was  in, let
me see …, October. It’s nothing to worry about of course;  pounds is an excellent weight for a
young woman your height. Let’s see, you’re what …, about  years old?
Nancy:
I’m .
Elaine:
Oh, right, of course. Your pulse is normal. Your blood pressure is a little low, but it’s within the
normal range. You do have a fever though—.. How do you feel?
Nancy:
I feel awful. I have a headache, and I ache all over.
Elaine:
Any nausea?
Nancy:
No, not really. But I sure don’t feel like eating. I guess that’s why I’ve lost a few pounds. I just feel
lousy. But I mean really lousy. It’s a couple of days now. I don’t get it—it’s not flu season, and I had
a shot, anyway.
Elaine:
Let’s see what the doctor says. She’ll be right in.
Narrator:
After a short wait, the doctor arrives and the following conversation ensues.
Dr. Ghee: Hi, Nancy. I haven’t seen you for a while. What seems to be the problem today?
Nancy:
Well, I got my flu shot last October. All of us got them. But it feels like I have the flu. I have
no appetite. I have killer headaches and everything hurts, even my bones! If I stop taking
acetaminophen, I get a fever. It’s been a few days now.
Dr. Ghee: When you say “all of us,” who do you mean …?
Nancy:
All of the nurses on my unit got flu shots—it’s required.
Dr. Ghee: Oh, right. You look so young I always think you’re still in college. It seems like you were shadowing
in this office only last year. But that can’t be right. I guess you’re a nurse now, right? So, what do
you think may be going on?
Narrator:
Nancy hesitates for a moment.
Nancy:
Dr. Ghee, I had a needlestick incident a week or so ago. It was minor, and the patient was HIV
negative and she didn’t have hepatitis. I didn’t think much of it, just cleaned the wound and filled
out a report.
Narrator:
Doctor Ghee looks grave.
Dr. Ghee: Do you know what the patient was hospitalized for, Nancy?
Nancy:
She had picked up a case of dengue on vacation abroad. You can’t get dengue from a needlestick, can you?
Dr. Ghee: Well, it’s possible, although I’ve never heard of it before. Let’s take a more thorough look at you and
do some blood work.
“The Unfortunate Nurse” by Karen M. Aguirre
Page 
Questions
. How does this story highlight the importance of taking a thorough medical and personal history of a
patient? What sorts of questions are important to ask someone who is ill?
. Why does the doctor want to take a “closer look” at Nancy? What sort of things might she look for?
. What exactly does “blood work” mean? What kind of tests is the doctor likely to order using the blood and
why? What about the urine and/or sputum sample?
Now look over the Figure and Table from the article you read; be sure you understand them and try to interpret the
results (see next page). The questions below are intended to guide your understanding of this material.
Further Questions
. What is a leukocyte? Are leukocytes raised or depleted in Nancy’s blood? What is the usual significance of
an elevated leukocyte count? What’s going on with the lymphocytes?
. An EIA (enzyme-linked-immunosorbent assay, sometimes also called an ELISA) is a frequently used
technique that allows medical personnel and researchers to identify and quantitate proteins such as
antibodies, antigens, or other immune system chemicals that are present in biological fluids. Antibodies are
proteins produced by white blood cells called B cells. They bind in a highly specific “lock and key” fashion
to viruses, bacteria, fungi, and to pieces of viruses, bacteria, and fungi. The immune system uses these
antibodies almost like handles that aid in clearance of the infecting organisms as well as to tag pathogens
and identify them as foreign, which also facilitates clearance and healing. There are several different classes
of antibody (or immunoglobulin, as the antibody protein is properly named), including IgM, IgG, IgD,
IgA and IgE. IgM is always present on the surface of resting B cells, and is the first class of antibody
secreted (released into the fluid portion of the blood) in response to infection. After the immune response
matures a bit, with the help of T lymphocytes, the predominant antibody class present switches to IgG.
In people who have been previously exposed to a pathogen, memory B cells exist, and these express IgG
bound to their cell membranes. Upon stimulation by re-infection, they differentiate into plasma cells that
secrete IgG that is directed against the pathogen. In the second set of results, EIA was used to quantify antidengue antibodies in Nancy’s blood. What do the results tell you? What new, complementary information
is gained from the EIA report?
. What is the significance of the RT-PCR results?
. What actions will Dr. Ghee take in treating Nancy?
Note: You may have some trouble answering Question . It’s hard to give advice if you don’t have enough background
information to make rational decisions. Please list some of the questions that you have about dengue and the related
condition known as dengue hemorrhagic fever (DHF). Also list any questions you may have about the techniques or
tests used in the journal article.
Homework Assignment
Dr. Ghee also did not know a lot about dengue because it is a disease not often encountered in American doctors’
offices. She went to the Centers for Disease Control (CDC) website and read about the history, immunology,
treatment, etc., for dengue. You will also be using this site as a point of departure to prepare PowerPoint presentations
answering some of the questions you have generated above.
We will divide up into groups. Each group will use information gained from the Resources in Part I to generate a short
PowerPoint presentation on a chosen/assigned topic from the list of questions generated. These will be presented at the
next class meeting, and eventually posted on the class website. Each group’s presentation will be graded according to
the Presentation Grading Rubric.
In addition, in order to receive credit for this assignment, the group must prepare a one-page summary hand-out for
the class and also post the PowerPoint presentation on the class website.
“The Unfortunate Nurse” by Karen M. Aguirre
Page 
Table
Laboratory data for index patient and health care worker infected with dengue virus*
Day
Index patient
Health care
worker
i
i
i
n
n
n
n
Leukocytes Lymphocytes
(mL)
(mL)
.

.
ND
.
.
.

.
.
.
.
.
.
Thrombocytes (mL)
.
.
.
.
Dengue
IgM EIA
–
+
+
–
Dengue IgG
EIA (U)
+ (.)
+ (.)
+ (.)
– (.)
Dengue
PCR
+
–
ND
+
.
.
.
+
+
+
– (.)
+ (.)
+ (.)
ND
ND
ND
*Ig, immunoglobulin; EIA, enyzyme immunosorbent assay; PCR, polymerase chain reaction; ND, not done.
Figure
Source: Wagner, D., de With, K., Huzly, D., Hufert, F., Weidmann, M., Breisinger, S., Eppinger, S., Kern, W.V., and
Tilman, M.B. . Nosocomial acquisition of dengue. Emerging Infectious Diseases ():–. Retrieved
from http://www.cdc.gov/ncidod/EID/volno/-.htm.
“The Unfortunate Nurse” by Karen M. Aguirre
Page 
Part II—Presentations
Each student group will give their presentations. When not presenting, you will be listening to and grading the other
groups’ presentation using the Presentation Grading Rubric to score each group. The instructor will also score each
group using the rubric and make the final assessment grade, taking into consideration the comments of the students.
The instructor will share the class comments with each group as well as the final assessment.
It is your job as a member of the “audience” to interact with the presenters, asking questions, etc., as appropriate. At
the end of the class session, each student will present a brief outline (about a page) telling what he/she now knows
about the facts and background of dengue, and what he/she would still like to learn.
Presentation Grading Rubric
Please evaluate the slide show presentations according to the following rubric.
Title: Have a title, please.
Content:  pts
____
Students set the topic in context, i.e., explained why this topic is important. ()
____
Students were able to deliver a coherent, detailed explanation for each figure shown. Students gave
background material (visually and/or verbally) to help audience understand the presented figures. ()
____
Students did an adequate job of answering questions from the audience. ()
Organization:  pts
____
Presentation was organized in a logical, easy-to-follow fashion. ()
____
Presentation had a good balance of visual/verbal material. ()
Presentation:  pts
____
Students spoke loudly and clearly. ()
____
Students made eye contact with members of the audience and attempted to engage them; they seemed to care
whether they held attention of the audience. (1)
____
Talk was neither too long nor to short, and was delivered at an even pace. (Practice your talk and time it; it
should be about  minutes long.) ()
In addition, in order to receive credit for this assignment, the group must prepare a one-page summary hand-out for
the class and also post the PowerPoint presentation on the class website.
“The Unfortunate Nurse” by Karen M. Aguirre
Page 
Part III—Dengue in a Social Context / Educating Stakeholders
Before Class
Students should read the January  article “Texas Lifestyle Limits Transmission of Dengue Virus” by P. Reiter et al., Emerging
Infectious Diseases, vol. , no., pp. – (http://-www.cdc.gov.mill.sjlibrary.org/ncidod/eid/volno/-.htm). Again,
as you read, circle terms that you do not understand and look up definitions for them using the On-Line Medical
Dictionary (http://www.nlm.nih.gov/medlineplus/mplusdictionary.html) or other sources. Do your best and we will
demystify the rest together in class.
In Class
We will start with a discussion of what we have learned about dengue and what challenges the disease presents to our society.
Questions
. Legal immigrants typically are tested for certain diseases. Obviously, people entering illegally undergo no
such screening. What concerns might that cause in light of recent immigration trends in the United States?
What would immigration watch-dog groups say about the cost to society of dengue? Can you think of
other examples of medical issues that become entangled in political considerations?
. From what you have read and the information we have presented in class on the incidence and
epidemiology of dengue and on dengue surveillance, do you think we are in much danger of a serious
dengue epidemic locally?
. Consider the Reiter article that you read before class. Describe the climatologic argument for considering
dengue as a limited danger. Describe the “life-style” argument.
. Optional, food for thought: Earlier in this case study, we saw dengue transmitted by a needlestick. Outside
of hospitals, dengue is transmitted from person to person via mosquito bite. Why is it that HIV, another
blood-borne virus, can be transmitted by needlestick, but is not transmitted by mosquito bite?
. Your instructor will give you a table or figure showing the National Institute of Health’s projected funding
budget for various diseases for . Look it over. Do you think each allocation is defensible? Explain how
politics can sometimes drive research funding decisions.
Homework Assignment
The following writing assignment is designed to demonstrate student mastery of the goals for this case study:
As a take-home project, design (with artwork and text) three short (no more than two sides of a page each!)
educational brochures on dengue—one appropriate for primary care physicians, a second intended to encourage
recently graduated researchers to pursue research in this field, and a third that is appropriate for laypeople who
maintain homes or plan to travel into areas where dengue is endemic. Begin sketching your plans in class. Some
information may be common to all three brochures and some will be quite different. Your instructor is available for
consultation.
Case copyright © by the National Center for Case Study Teaching in Science.
Originally published // at http://www.sciencecases.org/dengue/dengue.asp
Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.
“The Unfortunate Nurse” by Karen M. Aguirre
Page 